Background: The purpose of this study was to examine the outcome and complications of hypercoagulable patients undergoing free-flap transfer in the head and neck region. Methods:We retrospectively reviewed the data of 685 consecutive free-flap transfers in the head and neck region performed by a single surgical team at the Peking University School and Hospital of Stomatology between January 2013 and December 2018. Based on preoperative coagulation indices the patients were separated into two groups: those with hypercoagulablity (group A, n = 45) and those with normal coagulation indices (group B, n = 640). Demographic characteristics, thrombosis and flap failure were compared between the two groups. Chi-square test and repeated-measures ANOVA were used for data comparisons.Results:Microvascular thrombosis rate (P = 0.42) and free-flap success rate (P = 0.38) were not significantly different between the groups. The platelet count and activated partial thromboplastin time changed significantly during the perioperative period in the hypercoagulable group (repeated-measures ANOVA, P < 0.001 for both).Conclusions:Hypercoagulability does not seem to increase risk of free-flap failure in head and neck microsurgery provided standard anticoagulation protocols are followed.